Power switching for electronic device test equipment

ABSTRACT

An apparatus, system and method are provided for testing a battery-powered electronic device-under-test in a transport frame engaged with a test fixture. A transport frame power supply is arranged to provide power to the DUT in a pre-testing stage. A switching circuit is arranged to switch from the transport frame power supply to a test fixture power supply in response to receiving a power switching signal indicating satisfaction of a pre-testing condition. Power from the test fixture power supply can then be switched back to the first transport frame, or to a second transport frame, to begin testing a second DUT. The ability to start a DUT test without having to wait for the DUT to boot-up in the test fixture reduces test time and increases efficiency of use of test equipment.

FIELD

The present application relates generally to test equipment for batterypowered electronic devices, such as mobile devices. More particularly,the present application relates to power switching for such testequipment.

BACKGROUND

A battery-powered electronic device typically undergoes a number oftests prior to large scale production. Such tests can be performed on adevice-under-test (DUT), which is substantially similar with respect tofunctional components to the final production device, and in many casesis the final production device. For example, a mobile electronic devicetypically undergoes at least three tests: Radio Frequency Test, AudioFrequency Test, and Combined Functional Test. During the tests variousparameters are measured, such as current and voltage.

To measure the parameters accurately, the DUT is powered via an externalpower supply, and its internal battery is removed. The tests can not beperformed without having the device fully turned on. Some tests, such asa charging test, cannot be performed with the device's internal batteryin place.

The DUT can be placed in a transport frame, which mates with a testfixture powered by the external power supply. After the device isconnected with the external power supply, the device boots up since thedevice has been without battery power beforehand, and the tests areperformed. If the device is booted up prior to insertion in the fixture,the device will lose the connection and will have to boot up againbefore the test can be performed.

Once the test is completed, the device is disconnected from the powersupply and the next device is connected with the power supply. Uponbeing connected, the next device will boot up and the tests will beperformed. As such, every time a device is connected to the powersupply, the device boots up before tests can be performed.

DUT boot up can take 10-45 seconds, depending on the device. Since thetest time itself is only about 30 seconds-2 minutes, the boot upcontributes significant idle time to the overall testing process.Testing equipment and testing personnel are forced to remain idle whilethe device boots up, causing a bottleneck and preventing more devicesfrom being tested during a given time period.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations will now be described, by way of example only, withreference to the attached Figures, wherein:

FIG. 1 illustrates a block diagram of an apparatus for testing abattery-powered device-under-test in a test fixture according to animplementation of the present application.

FIG. 2 illustrates a block and circuit diagram of an apparatus fortesting a battery-powered device-under-test in a test fixture accordingto another implementation of the present application.

FIG. 3 illustrates an electrical circuit diagram of a switching circuiton a transport frame for testing a DUT according to an implementation.

FIG. 4 illustrates front perspective view of a transport frame fortesting a DUT according to an implementation of the present application.

FIG. 5 is a flowchart illustrating a method of power switching in asystem for testing a DUT according to an implementation of the presentapplication.

FIG. 6 illustrates a graphical plot of power usage in a DUT according toan implementation of the present application.

FIG. 7 illustrates a block diagram of a system for testing first andsecond DUTs according to an implementation of the present application.

FIGS. 8 and 9 are flowcharts illustrating a method of power switching ina system for testing first and second DUTs according to animplementation of the present application.

FIG. 10 is a block diagram of a mobile electronic device according toone example.

DETAILED DESCRIPTION

Generally, the present application provides a method and apparatus fortesting a battery-powered electronic device-under-test in a transportframe engaged with a test fixture. A transport frame power supply isarranged to provide power to the DUT in a pre-testing stage. A switchingcircuit is arranged to switch from the transport frame power supply to atest fixture power supply in response to receiving a power switchingsignal indicating satisfaction of a pre-testing condition. Power fromthe test fixture power supply can then be switched back to the firsttransport frame, or to a second transport frame, to begin testing asecond DUT. The ability to start a DUT test without having to wait forthe device to boot-up in the test fixture reduces test time andincreases efficiency of use of test equipment.

Implementations of the present application can reduce equipmentutilization per test, increase equipment utilization efficiency,increase production efficiency and decrease overall device testing cost.

For example, test equipment such as the Agilent 8960 Series 10 WirelessCommunications Test Set, cost about $35,000-$40,000 or more each.Keeping such equipment idle is a waste of expensive resources. Withoutredesigning the device operating system to reduce boot time,implementations of the present application can reduce test time byaddressing the contribution of such boot-up time. Such challenges arefaced by manufacturers of battery powered electronic devices, such asmobile device or mobile phone manufacturers, or any other entityoperating in a similar testing environment.

Implementations of the present application can be applied to testing anybattery-powered electronic device that has a boot up time.

A test station cannot communicate with a DUT and start testing until theDUT fully boots up. By booting up the DUT before plugging the DUT intotest station, a tester can communicate with the DUT immediately throughUSB and start testing.

In an implementation, the present application provides an apparatus fortesting a DUT, such as a mobile device, in a test fixture. The testfixture is arranged to receive the transport frame and to test the DUTwhen the transport frame is engaged with the test fixture. The testfixture includes a test fixture power supply arranged to provide powerto the electronic device in a testing stage. The apparatus includes atransport frame power supply arranged to provide power to the DUT in apre-testing stage, and a switching circuit. The switching circuit isarranged to switch from the transport frame power supply to the testfixture power supply in response to receiving a first power switchingsignal indicating satisfaction of a pre-testing condition, and arrangedto switch from the test fixture power supply to the transport framepower supply in response to receiving a second power switching signalindicating completion of a testing stage.

The apparatus can further include a switching controller to controlpower switching between the transport frame power supply and the testfixture power supply, the switching controller being arranged togenerate the first and second power switching signals. The switchingcontroller can be provided in the test fixture. The switching controllercan include a machine readable medium storing statements andinstructions for execution by a processor to control power switchingbetween the transport frame power supply and the test fixture powersupply.

The switch from the transport frame power supply to the test fixturepower supply can cause a voltage drop, and the switching circuit can bearranged such that the voltage drop is below a reboot tolerance for theDUT.

The switching circuit can include a load switch, such as a metal oxidesemiconductor field effect transistor (MOSFET). The switching circuitcan include an isolator arranged to electrically isolate the transportframe power supply from the test fixture power supply.

In another implementation, the present application provides a method ofpower switching in a system for testing a DUT, the system including atransport frame and a test fixture arranged to receive the transportframe and to test the DUT when the transport frame is engaged with thetest fixture. The method includes the following actions: providing powerto the DUT in a pre-testing stage via a transport frame power supplywhen the DUT is housed in the transport frame; switching from thetransport frame power supply to a test fixture power supply in responseto a first power switching signal indicating satisfaction of thepre-testing condition; and switching from the test fixture power supplyto the transport frame power supply in response to receiving a secondpower switching signal indicating completion of the testing stage.

The first power switching signal can include: an indication that thetransport frame is inserted in the test fixture and the test fixturepower supply is turned on; or an indication that the transport frame isinserted in the test fixture and the test fixture power supply is turnedon, and that the DUT is ready for initiation of the testing stage.

The method can include determining whether the pre-testing condition issatisfied. The method can further include initiating the testing stagein response to receiving a test initiation signal indicating the DUT isready for initiation of the testing stage. The method can includedetermining whether the DUT is ready for initiation of the testingstage. Determining whether the DUT is ready for initiation of thetesting stage can include receiving a determination that current drawnfrom the DUT is substantially similar to a known targeted idle currentof the DUT. The method can further include determining that currentdrawn from the DUT is substantially similar to a known targeted idlecurrent of the DUT.

The method can further include charging the transport frame powersupply.

In another implementation, the present application provides acomputer-readable medium storing statements and instructions forexecution by a processor to perform a method of power switching in asystem for testing a DUT as described herein.

In a further implementation, the present application provides a systemfor testing a battery-powered electronic device-under-test (DUT). Thesystem includes: a transport frame arranged to receive the DUT; atransport frame power supply arranged to provide power to the DUT in apre-testing stage; a test fixture arranged to receive the transportframe and to test the DUT when the transport frame is engaged with thetest fixture; a test fixture power supply arranged to provide power tothe electronic device after satisfaction of a pre-testing condition andin a testing stage; and a switching circuit. The switching circuit isarranged to switch from the transport frame power supply to the testfixture power supply in response to receiving a first power switchingsignal indicating satisfaction of the pre-testing condition, andarranged to switch from the test fixture power supply to the transportframe power supply in response to receiving a second power switchingsignal indicating completion of the testing stage.

The transport frame power supply can be provided within the transportframe. The test fixture power supply can be provided within the testfixture. The test fixture further include a charging circuit arranged tocharge the test fixture power supply, such as when the transport frameis plugged into test fixture or a special charging cradle.

Two powered-battery emulators can be provided for alternatively plugginginto fixture. When one battery emulator is in testing, the other one canboot up DUT first from a real battery on emulator. In a yet furtherimplementation, the present application provides a system for testingfirst and second battery-powered electronic devices-under-test,including: a first hot emulator arranged to receive the first DUT, thefirst hot emulator comprising a first battery arranged to provide powerto the first DUT in a first pre-testing stage; a second hot emulatorarranged to receive the second DUT, the second hot emulator comprising asecond battery arranged to provide power to the first DUT in a secondpre-testing stage; an external power supply, in electrical communicationwith the first and second hot emulators, and arranged to provide testingpower to the first and second DUTs during first and second testingstages, respectively; and a switching circuit arranged to switch thetesting power from the first hot emulator to the second hot emulator tobegin the second testing stage in response to receiving a first testcompletion signal indicating the first DUT has completed the firsttesting stage.

In an implementation, the present application provides a testing systemfor testing first and second battery-powered electronicdevices-under-test (DUTs). The system includes: first and secondtransport frames for receiving the first and second DUTs, the firsttransport frame including a first transport frame power supply and afirst switching circuit, and the second transport frame including asecond transport frame power supply and a second switching circuit; atest fixture arranged to receive the first and second transport framesand to test the first and second DUTs, respectively, when the first andsecond transport frames are engaged with the test fixture, the testfixture including a test fixture power supply; and a switchingcontroller in communication with the first and second switching circuitsand arranged to generate first and second power switching signals.

The first switching circuit is arranged to switch from the firsttransport frame power supply to the test fixture power supply inresponse to receiving a first power switching signal indicatingsatisfaction of the pre-testing condition, and arranged to switch fromthe test fixture power supply to the first transport frame power supplyin response to receiving a second power switching signal indicatingcompletion of a testing stage for the first DUT. The switchingcontroller is arranged to initiate power switching of power supplied bythe test fixture power supply from the first transport frame to thesecond transport frame to begin a testing stage for the second DUT.

The second switching circuit is arranged to switch from the secondtransport frame power supply to the test fixture power supply inresponse to receiving a third power switching signal indicatingsatisfaction of a second pre-testing condition, and arranged to switchfrom the test fixture power supply to the second transport frame powersupply in response to receiving a fourth power switching signalindicating completion of the testing stage for the second DUT. Theswitching controller is arranged to generate the third and fourth powerswitching signals.

In another implementation, the present application provides a method ofpower switching in a system for testing first and second DUTs, thesystem including first and second transport frames for receiving thefirst and second DUTs, respectively, and a test fixture arranged toreceive the first and second transport frames and to test the first andsecond DUTs, respectively, when the first and second transport framesare engaged with the test fixture. The method includes the followingactions: providing power to the first DUT in a pre-testing stage via afirst transport frame power supply when the DUT is housed in the firsttransport frame; switching from the first transport frame power supplyto a test fixture power supply in response to receiving a first powerswitching signal indicating satisfaction of a first pre-testingcondition; switching from the test fixture power supply to the firsttransport frame power supply in response to receiving a second powerswitching signal indicating completion of a testing stage for the firstDUT; switching from the second transport frame power supply to a testfixture power supply in response to receiving a third power switchingsignal indicating satisfaction of a second pre-testing condition; andswitching from the test fixture power supply to the second transportframe power supply in response to receiving a fourth power switchingsignal indicating completion of a testing stage for the second DUT.

FIG. 1 illustrates a block diagram of an apparatus for testing abattery-powered device-under-test in a test fixture according to animplementation of the present application. The apparatus 100 is fortesting a DUT 102 using a test fixture 104. The test fixture 104 isarranged to receive the apparatus, or transport frame, and to test theDUT when the apparatus is engaged with the test fixture 104. The testfixture includes a test fixture power supply, or external power supply,106 arranged to provide power to the DUT in a testing stage. Theapparatus 100 can be electrically connected to the test fixture, or testsystem, 104 via a USB connection.

The apparatus 100 includes a transport frame power supply 108 arrangedto provide power to the DUT in a pre-testing stage, or boot up stage. Inan implementation, the transport frame power supply 108 comprises abattery.

The apparatus 100 also includes a switching circuit 110 arranged toswitch from the transport frame power supply 108 to the test fixturepower supply 106 in response to receiving a first power switching signal112 indicating satisfaction of a pre-testing condition. The pre-testingcondition can comprise whether the transport frame is inserted in thetest fixture, and the test fixture power supply is turned on. Theapparatus can determine whether the DUT 102 is ready for initiation of atesting stage. The testing stage can comprise a current test. The powersupply for the DUT 102 is maintained during switching of the powersources. Power is switched from the test fixture power supply 106 to thetransport frame power supply 108 in response to receiving a second powerswitching signal 112A indicating completion of a testing stage.

The term “pre-testing stage” as used herein represents a stage thatprecedes the testing stage, and during which the pre-testing conditionhas not yet been satisfied. The transport frame power supply 108supplies power to the DUT 102 during the pre-testing stage. Power isswitched from the transport frame power supply 108 to the test fixturepower supply 106 in response to satisfaction of a pre-testing condition.This means that the test fixture power supply 106 can provide power tothe DUT 102 after the pre-testing condition has been satisfied and untilthe DUT is ready for testing, as well as during the actual testingstage. In other words, between the pre-testing stage and the testingstage, there can be an intermediate stage during which the pre-testingcondition has been satisfied, but the DUT is not ready for initiation ofthe testing stage. The transport frame power supply 108 provides powerto the DUT during such an intermediate stage.

Rather than switching due to loss of power from a primary power source,implementations of the present application switch power in response toreceipt of a first power switching signal 112, which can be generatedbased on a predetermined condition, or pre-testing condition, beingsatisfied. For example, the first power switching signal 112 can begenerated when the transport frame 100 is electrically engaged, or powerengaged, with the test fixture 104 and the test fixture power supply 106is turned on, regardless of whether the DUT 102 has completed boot up.

A switching controller 114 can control switching from the transportframe power supply 108 to the test fixture power supply 106. Theswitching controller 114 can generate the first and second powerswitching signals 112 and 112A received by the switching circuit 110, inresponse to which power is switched. The first power switching signal112 can be generated in response to satisfaction of a pre-testingcondition. In one implementation, the first power switching signal 112can be generated in response to manual actuation of a switch enablemeans by an operator, such manual actuation being the pre-testingcondition that is satisfied. The second power switching signal 112A canbe generated in response to completion of a testing stage.

The switching circuit 110 can perform an automatic switching between thetransport frame power supply 108 and the test fixture power supply 106in order to obtain or acquire current or voltage measurements for thetest.

The switching controller 114 can comprise a machine readable mediumstoring statements and instructions for execution by a processor tocontrol switching from the transport frame power supply to the testfixture power supply in response to receiving a first power switchingsignal indicating satisfaction of a pre-testing condition. In animplementation, the processor detects the presence of a transport frame100 that is engaged with the test fixture 104, and the test fixturepower supply 106 is turned on. The switching controller 114 can alsodetermine whether the DUT is ready for initiation of the testing stage.For example, the switching controller can detect a fully booted DUT,such as through current detection or polling for a connection. In anexample, the processor then initiates the testing stage. In animplementation, the switching controller 114 is implemented on apersonal computer (PC) and comprises a test sequence or test routine, orstatements and instructions for performing the test sequence.

The first power switching signal 112 can be generated in response to apositive connection polling result. For example, the switchingcontroller 114, or a test sequence provided therein, can poll the DUT102 until a positive connection polling result is obtained. In animplementation, a device driver on the PC can poll for a connection. Forexample, the test sequence in the switching controller 114 cancontinually request a connection to the DUT 102 from the device driver,or request connection to the first available DUT if there are two ormore being tested.

If the device driver is configured to allow for connection polling, thenpolling can continue until the connection is made, after the device isfully booted, or a timeout condition is reached. One example of such adevice driver configuration is that the device driver does not blockexecution of the test for a long period but returns with a negativeresponse. Alternatively, in a situation in which the device driverblocks execution of the sequence or causes some type of catastrophicerror, current detection can be used, and then connection polling. Thispolling can be performed either internally to the device driver orexternally in the test sequence.

The DUT 102 has a different current draw depending on whether the deviceis booting up, or has completed boot up. The determination of whetherthe DUT 102 is ready for initiation of the testing stage can be madebased on a determination that current drawn from the DUT 102 is stable,or that the current drawn is substantially similar to a known targetedidle current of the DUT, indicating that boot up has been completed andthe device is idle. The determination can be made at the switchingcontroller 114, which is preferably in communication with test fixturepower supply 106 to detect the current drawn therefrom. For example, inan implementation, the determination can be made by a PC test sequenceof the switching controller 114 which is in communication with the testfixture power supply 106 to detect the current drawn. This currentdetection is performed after the power has been switched to the testfixture power supply 106.

For example, when the transport frame 100, or emulator, is inserted intotest fixture 104, a test sequence can switch the power from thetransport frame power supply 108, such as a battery, to the power supply106. After the power switch over, a test sequence can start detectingthe current draw from the power supply 106 to determine if the DUT 102is fully booted up. If the current measurement is around a targeted idlecurrent of the DUT 102, the test sequence can start testing immediately.

In an example, a test sequence in the switching controller 114 polls thepower supply 106 at a predetermined interval until the current reachesthe idle threshold or until a timeout condition is reached. The testroutine can establish a connection to the device and executes the testsequence automatically once the current threshold is met.

According to an implementation of the present application, a battery isprovided in the apparatus as the transport frame power supply 108. Thisallows the device to be powered-up, using the battery 108 in thetransport frame 100, prior to its insertion in the test fixture in orderto perform the test. The DUT 102 can start testing immediately when theDUT 102 plugs in, instead of waiting for DUT 102 boot-up via theexternal power supply 106. This can reduce or eliminate the wait timeassociated with device boot-up time. For example, for a certain model ofDUT 102 that was tested for two years, the wait time reductioncorresponded to 530 days.

As mentioned earlier, in order to measure the device's current draw, anon-board battery cannot be inserted into the device during the test. Thetest fixture power supply 106 in conjunction with a switching controller114 are used to perform a current test, by measuring a drawing currentor a sinking current and determining if the device is working properly.An apparatus, or battery emulator, according to an implementation of thepresent application emulates the on-board battery performance for thepurposes of testing. Battery modules often use encryption such that onlya particular battery can be used with a given device. As such, atransport frame power supply 108 implemented as a battery can compriseencryption restricting use of the battery to a device model representedby the DUT 102.

In an implementation, the switching circuit 110 is arranged to switchpower from the battery to the power supply while minimizing aninterruption in current flow or a change in the voltage, and avoiding aloss of connection. If there is a large enough hiccup in the level ofpower supply, the DUT 102 will reboot. In an implementation, the switchfrom the transport frame power supply to the test fixture power supplycauses a voltage drop, and the switching circuit 110 is arranged suchthat the voltage drop is below a reboot tolerance for the DUT 102.

The tolerance in the switching is related to the device's tolerance forrebooting. In an exemplary device, a voltage below 2.5 volts for severalmilliseconds will trigger a reboot. Components or elements of theswitching circuit 110, and optionally the switching controller 114, areselected in order to achieve a voltage drop that is below the DUT'sreboot tolerance. For devices with different tolerances, the switchingcircuit 110, and optionally the switching controller 114, can bemodified accordingly, as is evident to one of ordinary skill in the art.

While functionality is described above and in examples as beingperformed by the switching controller 114, the switching controllerfunctionality can alternatively be performed by any other processor,computer or device in communication with the test fixture 104 and theDUT 102.

In an implementation, the switching controller 114 itself can beprovided outside of the test fixture 104, such as in the transport frame100 or in a separate device or apparatus. The location of the switchingcontroller 114, or switching controller functionality, can be anywherethat the switching controller is able to determine the inputs andoutputs of the system, such as having access to data from the powersupply 106 of the test fixture 104.

For example, if current is not being measured with the power supply, andrather using a current meter on the transport frame 100, the switchingcontroller 114 can be provided on the transport frame 100. In that case,the power supply measurement can be taken externally from the transportframe 100. As long as there is a manner in which current and voltage canbe measured on the transport frame 100, such as using a microcontrollerprovided on the transport frame 100, the determination can be made onthe transport frame 100 and power switching can be performedaccordingly.

FIG. 2 illustrates a block and circuit diagram of an apparatus fortesting a DUT in a test fixture according to another implementation ofthe present application. The implementation in FIG. 2 is similar to theimplementation in FIG. 1, and shows the apparatus in isolation from thetest fixture 104. In this example, the transport frame power supply 108is implemented as a battery. The switching circuit 110 receives theswitching signal 112 and power from the battery 108 and the test fixturepower supply 106.

An implementation of the present application includes: a battery; ameans for switching the power source of the device from the battery toan external power supply, such as provided by a base plate or testfixture; and a means for verifying that the device has fully turned onwhen the transport frame is connected with the base plate.

FIG. 3 illustrates an electrical circuit diagram of the switchingcircuit 110 on a transport frame 100 according to an implementation. InFIG. 3, a particular implementation is shown in detail, in which thetransport frame power supply is a battery. The switching circuit 110 inFIG. 3 can perform power switching without a drop in power that wouldtrigger a reboot. Using implementations described herein, the voltagedrop is very small and the power can be switched back and forth betweenthe battery 108 and the power supply 106.

In FIG. 3, a charging circuit 116 is arranged to charge the battery inthe transport frame. The charging circuit can provide charging currentfor a real battery on the transport frame, or emulator, to extendbattery lifetime on the transport frame. The charging circuit 116 can beturned on only when the + fixture power is connected, for example, +5 Vwhen transport frame 100 is inserted into test fixture 104. Providingthe charging circuit 116 gives an advantage that the battery need not bereplaced frequently. The charging circuit 116 can be provided in thetest fixture.

In FIG. 3, the switching circuit 110 can switch between the battery 108and the power supply 106 and isolate the two from each other. In animplementation, the switching circuit 110 comprises an ideal diode 118arranged to electrically isolate the transport frame power supply fromthe test fixture power supply.

The switching circuit 110 can comprise a load switch 120 having lowstatic Drain to Source on resistance, which has substantially no impacton current measurement for DUT test.

The load switch 120 can comprise a metal oxide semiconductor fieldeffect transistor (MOSFET), power MOS device or power FET. The loadswitch 120 has a small switch-over voltage loss and can be a p-channelMOSFET. The load switch 120 also works well as an isolating switch sincethe power consumption is very low, and the load switch 120 preventsbackup current to the test fixture power supply 106. When turning on thedevice, the voltage of battery 108 can be about 4.2 volts, which ishigher than the voltage of the power supply 106 of 3.8 volts. In thatcase, current can flow from the battery 108 to the test fixture powersupply 106, which is undesirable. Therefore, the load switch 120isolates the battery 108 from the test fixture power supply 106 toprevent current leakage there between. The load switch 120 can enablethe switching circuit 110 to carry out a method of instantaneouslyswitching the device's power source from a battery 108 in the testmodule to the external power supply 106.

Alternatives to using a load switch 120 include a basic switch, or adiode connected to both the battery and the power supply. In some cases,the use of a diode in the fixture can trigger a power supply protectionfault because some of the battery voltage trickles over to the powersupply. Also, using a diode for switching has the drawback of a 0.7 Vdrop across a diode, meaning that the diode may not work for thepurposes desired.

An advantage of using a load switch for switching is that the loadswitch is better than using relay-capacitor combination, since relaysget worn out, have bigger metal parts and the combination alters theradiated RF characteristics of the DUT, leading to inaccurate RFmeasurements. A load switch has low static Drain to Source onresistance, which has substantially no impact on current measurement fordevice test.

FIG. 4 illustrates front perspective view of a transport frame fortesting a DUT according to an implementation of the present application.This figure illustrates an example of a visual representation of atransport frame 100, and the location of a transport frame power supply108, or battery, in a position distinct from the location in which theDUT is placed (on the opposite side not shown in FIG. 4). The battery108 can have an associated connector 122 to connect with circuitry onthe transport frame 100.

According to an implementation described herein, even when the transportframe 100 is not attached with a base plate or test fixture 104, the DUTcan receive power from the transport frame power supply 108. So, adevice resting in the transport frame can be turned on even when thetransport frame is not attached with the base plate or test fixture, andpermit boot up prior to testing, such that the device will not require areboot after power switching.

An example implementation of the present application includes fourcomponents, in addition to the primary components described earlier: 1)Load Switch 120. The present application includes a means for switchingthe power source of the device from the transport-frame battery 108 tothe base plate. This maintains power supply for the device during powerswitching by using a Load Switch 120 for power switching between a realbattery 108 and test fixture power supply 106; 2) An ideal diode 118 isconnected between battery 108 and Load Switch 120 to prevent backwardcurrent from power supply. The ideal diode 118 has very low voltage dropand Forward-on-Resistance across the ideal diode 118 during normaloperation. 3) To extend battery lifetime on transport frame, a chargingcircuit 116 provides charging current for real battery 108. 4) A meansfor verifying that the device is turned on and fully booted up. Themeans comprises monitoring the current drawn through the base plate fromtest fixture power supply 106, after power has been switched thereto,and detecting a current which is below a predetermined currentthreshold. Once the current is detected to be below the threshold thenthe test sequence is automatically started.

FIG. 5 is a flowchart illustrating a method of power switching in asystem for testing a DUT according to an implementation of the presentapplication. The system can include a transport frame 100 and a testfixture 104 arranged to receive the transport frame 100 and to test theDUT 102 when the transport frame 100 is engaged with the test fixture104. The method comprises: providing power to the DUT in a pre-testingstage via a transport frame power supply 108 when the DUT 102 is housedin the transport frame 100 (action 124); switching from the transportframe power supply 108 to a test fixture power supply 106 in response toreceiving a first power switching signal indicating satisfaction of apre-testing condition (action 126); and switching from the test fixturepower supply to the transport frame power supply in response toreceiving a second power switching signal indicating completion of atesting stage (action 128).

The method can include determining whether the pre-testing condition issatisfied (action 130). This action 130 can be performed after action124. For example, action 130 can include determining whether thetransport frame is inserted in the test fixture, and the test fixturepower supply is turned on.

The method can further include determining whether the DUT is ready forinitiation of the testing stage (action 132). Such determination can bemade on the basis of whether the current drawn from the DUT issubstantially similar to a known targeted idle current of the DUT. Forexample, action 132 can include receiving a determination that currentdrawn from the DUT 102 is substantially similar to a known targeted idlecurrent of the DUT. Action 132 is performed after action 126, since thecurrent can be read or determined from the test fixture power supply 106only after power is switched to the test fixture power supply 106 inaction 126.

The method in FIG. 5 can include initiating the testing stage inresponse to receiving a test initiation signal indicating the DUT isready for initiation of the testing stage (action 134). The action 134is performed after action 132, and the test initiation signal can begenerated based on the determination in action 132. The method can alsoinclude determining whether the testing stage is complete (action 136).The action 136 is performed after the action 134, and the second powerswitching signal received in action 128 can be generated based on thedetermination in action 136.

FIG. 6 illustrates an exemplary graphical plot, 140 generated by anoscilloscope, of power usage in a DUT according to an implementation ofthe present application. The power used by the DUT is shown on the plotas a DUT power usage signal 142. A first portion 144 of the DUT powerusage signal 142 represents the power applied to the DUT using thetransport frame power supply 108. When the switching signal 112, orswitch enable signal, changes from LOW TO HIGH, power applied to the DUTis changed from the transport frame power supply 108 to the test fixturepower supply 106. The resulting power applied is shown in a secondportion 146of the displayed DUT power usage signal 142. The voltagelevel provided to the DUT is changed from 4.1V in the first portion 144to 3.8V in the second portion 146. A transition period 148 can be about0.3 milliseconds, as shown in the plot from oscilloscope in FIG. 6.

When testing products in a production line, each separate product canhave at least one production line. Each production line can have about10-30 test fixtures. In an implementation, more than one transportframe, or hot emulator, can advantageously be provided for each station.The description below will discuss having two transport frames. In anexemplary operation in which the test time is 6 seconds and the deviceboot-up time is 10 seconds, 3 or 4 transport frames can advantageouslybe used with each test fixture.

In an implementation, the present application provides a system fortesting first and second battery-powered electronic DUTs, including afirst hot emulator arranged to receive the first DUT, and a second hotemulator arranged to receive the second DUT. The first hot emulatorcomprises a first battery arranged to provide power to the first DUT ina first pre-testing stage. The second hot emulator comprises a secondbattery arranged to provide power to the first DUT in a secondpre-testing stage. An external power supply is provided, in electricalcommunication with the first and second hot emulators, and arranged toprovide testing power to the first and second DUTs during first andsecond testing stages, respectively. A switching circuit is arranged toswitch the testing power from the first hot emulator to the second hotemulator to begin the second testing stage in response to receiving afirst test completion signal indicating the first DUT has completed thefirst testing stage.

FIG. 7 illustrates a block diagram of a system for testing first andsecond DUTs according to an implementation of the present application.The system includes first and second transport frames 100 and 130 forreceiving the first and second DUTs 102 and 152, respectively. The testfixture 104 of FIG. 7 is arranged to receive the first and secondtransport frames 100 and 150 and to test the first and second DUTs 102and 152, respectively, when the first and second transport frames areengaged with the test fixture 104. The test fixture 104 includes a testfixture power supply 106.

The first transport frame 100 includes a first transport frame powersupply 108 and a first switching circuit 110. The second transport frame150 includes a second transport frame power supply 158 and a secondswitching circuit 160.

A switching controller 114, in communication with the first and secondswitching circuits 110 and 160, is arranged to generate first and secondpower switching signals 112 and 112A, and third and further powerswitching signals 162 and 162A, respectively. The switching controller114 is also arranged to initiate power switching of power supplied bythe test fixture power supply 106 from the first transport frame 100 tothe second transport frame 150 to begin the second testing stage.

The first switching circuit 110 is arranged to switch from the firsttransport frame power supply 108 to the test fixture power supply 106 inresponse to receiving a first power switching signal 112 indicatingsatisfaction of the pre-testing condition, and arranged to switch fromthe test fixture power supply 106 to the first transport frame powersupply 108 in response to receiving a second power switching signalindicating completion of a testing stage for the first DUT 102.

The second switching circuit 160 is arranged to switch from the secondtransport frame power supply 158 to the test fixture power supply 106 inresponse to receiving the second power switching signal 162.

While the switching controller 114 is shown in FIG. 7 to be providedwithin the test fixture, the switching controller 114 can be provided inany other element of the test system, provided the other element has theappropriate electrical connections and ability to receive and generateinputs and outputs. Also, while functionality is described above and inexamples as being performed by the switching controller 114, theswitching controller functionality can alternatively be performed by anyother processor, computer or device in communication with the testfixture 104 and the DUTs 102 and 152.

FIGS. 8 and 9 are flowcharts illustrating a method of power switching ina system for testing first and second DUTs according to animplementation of the present application. The system includes first andsecond transport frames 100 and 150 for receiving the first and secondDUTs 102 and 152, respectively, and a test fixture 104 arranged toreceive the first and second transport frames 100 and 150 and to testthe first and second DUTs 102 and 152, respectively, when the first andsecond transport frames 100 and 150 are engaged with the test fixture104.

The method in FIG. 8 comprises: providing power to the first DUT 102 ina pre-testing stage via a first transport frame power supply 108 whenthe DUT 102 is housed in the first transport frame 100 (action 164);switching from the first transport frame power supply 108 to a testfixture power supply 106 in response to receiving a first powerswitching signal indicating satisfaction of a first pre-testingcondition (action 166); and switching from the test fixture power supply106 to the first transport frame power supply 108 in response toreceiving a second power switching signal indicating completion of atesting stage for the first DUT (action 168).

The method can include determining whether the first pre-testingcondition is satisfied (action 170). This action 170 can be performedafter action 164. For example, action 170 can include determiningwhether the first transport frame is inserted in the test fixture, andthe test fixture power supply is turned on.

The method can further include determining whether the first DUT isready for initiation of the testing stage (action 172). Suchdetermination can be made on the basis of whether the current drawn fromthe first DUT is substantially similar to a known targeted idle currentof the first DUT. For example, action 172 can include receiving adetermination that current drawn from the first DUT 102 is substantiallysimilar to a known targeted idle current of the first DUT. Action 172 isperformed after action 166, since the current from the test fixturepower supply 106 can be read or determined only after power is switchedto the test fixture power supply 106 in action 166.

The method in FIG. 8 can include initiating the testing stage for thefirst DUT in response to receiving a first test initiation signalindicating the first DUT is ready for initiation of the testing stage(action 174). The action 174 is performed after action 172, and thefirst test initiation signal can be generated based on the determinationin action 172. The method can also include determining whether thetesting stage for the first DUT is complete (action 176). The action 176is performed after the action 174, and the second power switching signalreceived in action 168 can be generated based on the determination inaction 176.

After completion of action 168 in FIG. 8, the method proceeds to FIG. 9.The actions in FIG. 9 are similar to those in FIG. 8, and relateprimarily to the second DUT 152. Action 178 of providing power to thesecond DUT 152 in a pre-testing stage via a second transport frame powersupply 158 can already be in process before the method proceeds fromaction 168 in FIG. 8.

The method in FIG. 9B comprises: switching from the second transportframe power supply 158 to a test fixture power supply 106 in response toreceiving a third power switching signal indicating satisfaction of asecond pre-testing condition (action 180); and switching from the testfixture power supply 106 to the second transport frame power supply 158in response to receiving a fourth power switching signal indicatingcompletion of a testing stage for the second DUT 152 (action 182).

The method can include determining whether the first pre-testingcondition is satisfied (action 184). This action 184 can be performedafter action 178 and after completion of action 168 in FIG. 8. Forexample, action 184 can include determining whether the second transportframe is inserted in the test fixture, and the test fixture power supplyis turned on.

The method can further include determining whether the second DUT isready for initiation of the testing stage (action 186). Suchdetermination can be made on the basis of whether the current drawn fromthe second DUT is substantially similar to a known targeted idle currentof the second DUT. For example, action 186 can include receiving adetermination that current drawn from the second DUT 152 issubstantially similar to a known targeted idle current of the secondDUT. Action 186 is performed after action 180, since the current fromthe test fixture power supply 106 can be read or determined only afterpower is switched to the test fixture power supply 106 in action 180.

The method in FIG. 9 can include initiating the testing stage for thesecond DUT in response to receiving a second test initiation signalindicating the second DUT is ready for initiation of the testing stage(action 188). The action 188 is performed after action 186, and thesecond test initiation signal can be generated based on thedetermination in action 186. The method can also include determiningwhether the testing stage for the second DUT is complete (action 190).The action 190 is performed after the action 188, and the fourth powerswitching signal received in action 182 can be generated based on thedetermination in action 190.

FIG. 10 is a block diagram of the mobile electronic device according toone example. The following describes in further detail an exemplarymobile electronic device that can include a processor, and a computerreadable memory in communication with the processor. In animplementation, the memory can store statements and instructions forexecution by the processor to identify an intended hard key activationin response to receiving an indication of connection of a key circuitand based on one or more detected capacitance levels, as described andillustrated in the present application. The mobile electronic device maybe a two-way communication device with advanced data communicationcapabilities including the capability to communicate with other mobileelectronic devices or computer systems through a network of transceiverstations. The mobile electronic device may also have the capability toallow voice communication. Depending on the functionality provided bythe mobile electronic device, the device may be referred to as a datamessaging device, a two-way pager, a cellular telephone with datamessaging capabilities, a wireless Internet appliance, or a datacommunication device (with or without telephony capabilities). Themobile electronic device may also be a mobile electronic device withoutwireless communication capabilities as a handheld electronic gamedevice, digital photograph album, digital camera and the like.

Referring to FIG. 10, there is shown therein a block diagram of anexemplary implementation of the mobile electronic device 300. The mobileelectronic device 300 includes a number of components such as aprocessor 308 that controls the overall operation of the mobileelectronic device 300. Communication functions, including data and voicecommunications, are performed through a communication subsystem 324.Data received by the mobile electronic device 300 can be decompressedand decrypted by a decoder 326, operating according to any suitabledecompression techniques (e.g. YK decompression, and other knowntechniques) and encryption techniques (e.g. using an encryptiontechnique such as Data Encryption Standard (DES), Triple DES, orAdvanced Encryption Standard (AES)). The communication subsystem 324receives messages from and sends messages to a wireless network 1000. Inthis exemplary implementation of the mobile electronic device 300, thecommunication subsystem 324 is configured in accordance with the GlobalSystem for Mobile Communication (GSM) and General Packet Radio Services(GPRS) standards. The GSM/GPRS wireless network is used worldwide. Newstandards such as Enhanced Data GSM Environment (EDGE) and UniversalMobile Telecommunications Service (UMTS) are believed to havesimilarities to the network behavior described herein, and personsskilled in the art will understand that the implementations describedherein are intended to use any other suitable standards that aredeveloped in the future. The wireless link connecting the communicationsubsystem 324 with the wireless network 1000 represents one or moredifferent Radio Frequency (RF) channels, operating according to definedprotocols specified for GSM/GPRS communications. With newer networkprotocols, these channels are capable of supporting both circuitswitched voice communications and packet switched data communications.

Although the wireless network 1000 associated with the mobile electronicdevice 300 is a GSM/GPRS wireless network in one exemplaryimplementation, other wireless networks may also be associated with themobile electronic device 300 in variant implementations. The differenttypes of wireless networks that may be employed include, for example,data-centric wireless networks, voice-centric wireless networks, anddual-mode networks that can support both voice and data communicationsover the same physical base stations. Combined dual-mode networksinclude, but are not limited to, Code Division Multiple Access (CDMA) orCDMA1000 networks, GSM/GPRS networks (as mentioned above), and futurethird-generation (3G) networks like EDGE and UMTS. Some other examplesof data-centric networks include WiFi 802.11, Mobitex™ and DataTAC™network communication systems. Examples of other voice-centric datanetworks include Personal Communication Systems (PCS) networks like GSMand Time Division Multiple Access (TDMA) systems. The processor 308 alsointeracts with additional subsystems such as a Random Access Memory(RAM) 328, a flash memory 330, a display 332, the keyboard 302, a switch339, an auxiliary input/output (I/O) subsystem 340, a data port 342, aspeaker 344, a microphone 346, short-range communications 348, and otherdevice subsystems 350. The flash memory 330 and RAM 328 are examples ofa computer readable memory in communication with the processor 308. Thememory can store statements and instructions for execution by theprocessor to perform the method of identifying an intended hard keyactivation in response to receiving an indication of connection of a keycircuit and based on one or more detected capacitance levels, asdescribed and illustrated in the present application

Some of the subsystems of the mobile electronic device 300 performcommunication-related functions, whereas other subsystems may provide“resident” or on-device functions. By way of example, the keyboard 302may be used for both communication-related functions, such as entering atext message for transmission over the network 1000, and device-residentfunctions such as a calculator or task list.

The mobile electronic device 300 can send and receive communicationsignals over the wireless network 1000 after network registration oractivation procedures have been completed. Network access is associatedwith a subscriber or user of the mobile electronic device 300. Toidentify a subscriber according to the present implementation, themobile electronic device 300 uses a SIM/RUIM card 352 (i.e. SubscriberIdentity Module or a Removable User Identity Module) inserted into aSIM/RUIM interface 354 for communication with a network such as thenetwork 1000. The SIM/RUIM card 352 is one type of a conventional “smartcard” that can be used to identify a subscriber of the mobile electronicdevice 300 and to personalize the mobile electronic device 300, amongother things. In the present implementation the mobile electronic device300 is not fully operational for communication with the wireless network1000 without the SIM/RUIM card 352. By inserting the SIM/RUIM card 352into the SIM/RUIM interface 354, a subscriber can access all subscribedservices. Services may include: web browsing and messaging such ase-mail, voice mail, Short Message Service (SMS), and MultimediaMessaging Services (MMS). More advanced services may include: point ofsale, field service and sales force automation. The SIM/RUIM card 352includes a processor and memory for storing information. Once theSIM/RUIM card 352 is inserted into the SIM/RUIM interface 354,theSIM/RUIM card 352 is coupled to the processor 308. In order to identifythe subscriber, the SIM/RUIM card 352 can include some user parameterssuch as an International Mobile Subscriber Identity (IMSI). An advantageof using the SIM/RUIM card 352 is that a subscriber is not necessarilybound by any single physical mobile electronic device. The SIM/RUIM card352 may store additional subscriber information for a mobile electronicdevice as well, including datebook (or calendar) information and recentcall information. Alternatively, user identification information canalso be programmed into the flash memory 330. The mobile electronicdevice 300 can also be enabled to receive additional memory cards. Forexample, memory card slots (not shown) can be provided in the mobileelectronic device 300 to receive such cards.

The mobile electronic device 300 is a battery-powered device andincludes a battery interface 356 for receiving a battery pack containingone or more rechargeable battery cells 358, and associated controlcircuitry (not shown) that, in some implementations, can interface withthe battery interface 356. The battery pack has a form factor andcontact arrangement suited to the particular mobile electronic device.In at least some implementations, the battery 358 can be a smart batterywith an embedded microprocessor. The battery interface 356 is coupled toa regulator (not shown), which assists the battery 358 in providingpower V+ to the mobile electronic device 300. Although currenttechnology makes use of a battery, future technologies such as microfuel cells may provide the power to the mobile electronic device 300.

The mobile electronic device 300 also includes an operating system 360and software components 362 which are described in more detail below.The operating system 360 and the software components 362 that areexecuted by the processor 308 are typically stored in a persistent storesuch as the flash memory 330, which may alternatively be a read-onlymemory (ROM) or similar storage element (not shown). Those skilled inthe art will appreciate that portions of the operating system 360 andthe software components 362, such as specific software applications 364,366, 368, 370 and 372, or parts thereof, may be temporarily loaded intoa volatile store such as the RAM 328. Other software components can alsobe included, as is well known to those skilled in the art.

The subset of software components 362 that control basic deviceoperations, including data and voice communication applications, willnormally be installed on the mobile electronic device 320 during itsmanufacture. Other software applications include a message application364 that can be any suitable software program that allows a user of themobile electronic device 300 to send and receive electronic messages.Various alternatives exist for the message application 364 as is wellknown to those skilled in the art. Messages that have been sent orreceived by the user are typically stored in the flash memory 330 of themobile electronic device 300 or some other suitable storage element inthe mobile electronic device 300. In at least some implementations, someof the sent and received messages may be stored remotely from the device300 such as in a data store of an associated host system that the mobileelectronic device 300 communicates with.

The software components 362 can further include a device state module366, a Personal Information Manager (PIM) 368, and other suitablemodules (not shown). The device state module 366 provides persistence,i.e. the device state module 366 ensures that important device data isstored in persistent memory, such as the flash memory 330, so that thedata is not lost when the mobile electronic device 300 is turned off orloses power.

The PIM 368 includes functionality for organizing and managing dataitems of interest to the user, such as, but not limited to, e-mail,contacts, calendar events, voice mails, appointments, and task items.The PIM 368 has the ability to send and receive data items via thewireless network 1000. PIM data items may be seamlessly integrated,synchronized, and updated via the wireless network 1000 with the mobileelectronic device subscriber's corresponding data items stored orassociated, or both, with a host computer system. This functionalitycreates a mirrored host computer on the mobile electronic device 330with respect to such items. This can be particularly advantageous whenthe host computer system is the mobile electronic device subscriber'soffice computer system.

The software components 362 also include a connect module 370, and aninformation technology (IT) policy module 372. The connect module 370implements the communication protocols that are required for the mobileelectronic device 300 to communicate with the wireless infrastructureand any host system, such as an enterprise system, that the mobileelectronic device 300 is authorized to interface with.

The connect module 370 includes a set of APIs that can be integratedwith the mobile electronic device 300 to allow the mobile electronicdevice 300 to use any number of services associated with the enterprisesystem. The connect module 370 allows the mobile electronic device 300to establish an end-to-end secure, authenticated communication pipe withthe host system. A subset of applications for which access is providedby the connect module 370 can be used to pass IT policy commands fromthe host system to the mobile electronic device 300. This can be done ina wireless or wired manner. These instructions can then be passed to theIT policy module 372 to modify the configuration of the device 300.Alternatively, in some cases, the IT policy update can also be done overa wired connection.

Other types of software applications can also be installed on the mobileelectronic device 300. These software applications can be third partyapplications, which are added after the manufacture of the mobileelectronic device 300. Examples of third party applications includegames, calculators, utilities, etc.

The additional applications can be loaded onto the mobile electronicdevice 300 through at least one of the wireless network 1000, theauxiliary I/O subsystem 340, the data port 342, the short-rangecommunications subsystem 248, or any other suitable device subsystem350. This flexibility in application installation increases thefunctionality of the mobile electronic device 300 and may provideenhanced on-device functions, communication-related functions, or both.For example, secure communication applications may enable electroniccommerce functions and other such financial transactions to be performedusing the mobile electronic device 300.

The data port 342 enables a subscriber to set preferences through anexternal device or software application and extends the capabilities ofthe mobile electronic device 300 by providing for information orsoftware downloads to the mobile electronic device 300 other thanthrough a wireless communication network. The alternate download pathmay, for example, be used to load an encryption key onto the mobileelectronic device 300 through a direct and thus reliable and trustedconnection to provide secure device communication.

The data port 342 can be any suitable port that enables datacommunication between the mobile electronic device 300 and anothercomputing device. The data port 342 can be a serial or a parallel port.In some instances, the data port 342 can be a USB port that includesdata lines for data transfer and a supply line that can provide acharging current to charge the battery 358 of the mobile electronicdevice 300.

The short-range communications subsystem 348 provides for communicationbetween the mobile electronic device 300 and different systems ordevices, without the use of the wireless network 1000. For example, theshort-range communications subsystem 348 may include an infrared deviceand associated circuits and components for short-range communication.Examples of short-range communication standards include standardsdeveloped by the Infrared Data Association (IrDA), Bluetooth, and the802.11 family of standards developed by IEEE.

Synchronization of files and data between the mobile electronic device300 and another computing device can be achieved over the wirelessnetwork 1000, through the short-range communications system 348, orthrough a direct connection between the data port 342 of the mobileelectronic device 300 and the other computing device. Synchronizationcauses the most recent version of files and data to be mirrored oneither the mobile electronic device or the other computing device. Asused herein, synchronization also refers to the downloading or uploadingof pre-selected files from one device to the other. Synchronization offiles and data can be initiated by the user of the device whenever asuitable connection between the mobile electronic device 300 and anothercomputing device, such as a home computer, is detected, or can occurautomatically when a connection is detected. A synchronizationapplication, stored in the mobile electronic device 300 or the othercomputing device, or both, can determine the file and data types to besynchronized, the frequency of synchronization, and other parameters,appropriate to the particular synchronization algorithm implemented bythe synchronization application.

In use, a received signal such as a text message, an e-mail message, orweb page download is processed by the communication subsystem 324 andinput to the processor 308. The processor 308 then processes thereceived signal for output to the display 332 or alternatively to theauxiliary I/O subsystem 340. A subscriber may also compose data items,such as e-mail messages, for example, using a touch-sensitive overlay(not shown) on the display 332 that is part of a touch screen display,and possibly the auxiliary I/O subsystem 340. The auxiliary I/Osubsystem 340 may include devices such as: a mouse, track ball, opticalnavigation module, infrared fingerprint detector, or a roller wheel withdynamic button pressing capability. A composed item may be transmittedover the wireless network 1000 through the communication subsystem 324.

For voice communications, the overall operation of the mobile electronicdevice 300 is substantially similar, except that the received signalsare output to the speaker 344, and signals for transmission aregenerated by the microphone 346. Alternative voice or audio I/Osubsystems, such as a voice message recording subsystem, can also beimplemented on the mobile electronic device 300 Although voice or audiosignal output is accomplished primarily through the speaker 344, thedisplay 332 can also be used to provide additional information such asthe identity of a calling party, duration of a voice call, or othervoice call related information.

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe implementations described herein. However, one skilled in the artwill understand that these specific details are not required in order topractice the implementations. In other instances, well-known electricalstructures and circuits are shown in block diagram form in order not toobscure the implementations. For example, specific details are notprovided as to whether the implementations described herein areimplemented as a software routine, hardware circuit, firmware, or acombination thereof.

Implementations described herein can be represented as a softwareproduct stored in a machine-readable medium (also referred to as acomputer-readable medium, a processor-readable medium, or a computerusable medium having a computer-readable program code embodied therein).The machine-readable medium can be any suitable tangible medium,including magnetic, optical, or electrical storage medium including adiskette, compact disk read only memory (CD-ROM), memory device(volatile or non-volatile), or similar storage mechanism. Themachine-readable medium can contain various sets of instructions, codesequences, configuration information, or other data, which, whenexecuted, cause a processor to perform actions in a method according toan implementation described herein. Those of ordinary skill in the artwill appreciate that other instructions and operations necessary toimplement the described implementations can also be stored on themachine-readable medium. Software running from the machine-readablemedium can interface with circuitry to perform the described tasks.

The above-described implementations are intended to be examples only.Alterations, modifications and variations can be effected to theparticular implementations by those of skill in the art withoutdeparting from the scope, which is defined solely by the claims appendedhereto.

1. An apparatus for testing a battery-powered electronicdevice-under-test (DUT) in a test fixture, the test fixture arranged toreceive the transport frame and to test the DUT when the transport frameis engaged with the test fixture, the test fixture comprising a testfixture power supply arranged to provide power to the DUT in a testingstage, the apparatus comprising: a transport frame power supply arrangedto provide power to the DUT in a pre-testing stage; and a switchingcircuit arranged to switch from the transport frame power supply to thetest fixture power supply in response to receiving a first powerswitching signal indicating satisfaction of a pre-testing condition, andarranged to switch from the test fixture power supply to the transportframe power supply in response to receiving a second power switchingsignal indicating completion of a testing stage.
 2. The apparatus ofclaim 1 further comprising a switching controller to control powerswitching between the transport frame power supply and the test fixturepower supply, the switching controller being arranged to generate thefirst and second power switching signals.
 3. The apparatus of claim 2wherein the switching controller is provided in the test fixture.
 4. Theapparatus of claim 2 wherein the switching controller comprises amachine readable medium storing statements and instructions forexecution by a processor to control power switching between thetransport frame power supply and the test fixture power supply.
 5. Theapparatus of claim 1 wherein the switching circuit comprises a loadswitch.
 6. The apparatus of claim 5 wherein the load switch comprises ametal oxide semiconductor field effect transistor (MOSFET).
 7. Theapparatus of claim 1 wherein the switch from the transport frame powersupply to the test fixture power supply causes a voltage drop, andwherein the switching circuit is arranged such that the voltage drop isbelow a reboot tolerance for the DUT.
 8. The apparatus of claim 1wherein the switching circuit comprises an isolator arranged toelectrically isolate the transport frame power supply from the testfixture power supply.
 9. The apparatus of claim 1 wherein the transportframe power supply comprises a battery.
 10. The apparatus of claim 9wherein the battery comprises encryption restricting use of the batteryto a device model represented by the DUT.
 11. The apparatus of claim 1wherein the battery-powered electronic device-under-test comprises amobile device.
 12. A method of power switching in a system for testing abattery-powered electronic device-under-test (DUT), the system includinga transport frame and a test fixture arranged to receive the transportframe and to test the DUT when the transport frame is engaged with thetest fixture, the method comprising: providing power to the DUT in apre-testing stage via a transport frame power supply when the DUT ishoused in the transport frame; switching from the transport frame powersupply to a test fixture power supply in response to a first powerswitching signal indicating satisfaction of the pre-testing condition;and switching from the test fixture power supply to the transport framepower supply in response to receiving a second power switching signalindicating completion of the testing stage.
 13. The method of claim 12wherein the first power switching signal comprises an indication thatthe transport frame is inserted in the test fixture and the test fixturepower supply is turned on.
 14. The method of claim 12 further comprisingdetermining whether the pre-testing condition is satisfied.
 15. Themethod of claim 12 further comprising initiating the testing stage inresponse to receiving a test initiation signal indicating the DUT isready for initiation of the testing stage.
 16. The method of claim 12further comprising determining whether the DUT is ready for initiationof the testing stage.
 17. The method of claim 16 wherein determiningwhether the DUT is ready for initiation of the testing stage comprisesreceiving a determination that current drawn from the DUT issubstantially similar to a known targeted idle current of the DUT. 18.The method of claim 16 further comprising determining that current drawnfrom the DUT is substantially similar to a known targeted idle currentof the DUT.
 19. A computer-readable medium storing statements andinstructions for execution by a processor to perform the method of claim12.
 20. A system for testing a battery-powered electronicdevice-under-test (DUT), comprising: a transport frame arranged toreceive the DUT; a transport frame power supply arranged to providepower to the DUT in a pre-testing stage; a test fixture arranged toreceive the transport frame and to test the DUT when the transport frameis engaged with the test fixture; a test fixture power supply arrangedto provide power to the DUT after satisfaction of a pre-testingcondition; and a switching circuit arranged to switch from the transportframe power supply to the test fixture power supply in response toreceiving a first power switching signal indicating satisfaction of thepre-testing condition, and arranged to switch from the test fixturepower supply to the transport frame power supply in response toreceiving a second power switching signal indicating completion of thetesting stage.
 21. The system of claim 20 wherein the transport framepower supply is provided within the transport frame.
 22. The system ofclaim 20 wherein the test fixture power supply is provided within thetest fixture.
 23. The system of claim 20 wherein the test fixturefurther comprises a charging circuit arranged to charge the test fixturepower supply.
 24. A testing system for testing first and secondbattery-powered electronic devices-under-test (DUTs), comprising: firstand second transport frames for receiving the first and second DUTs, thefirst transport frame including a first transport frame power supply anda first switching circuit, the second transport frame including a secondtransport frame power supply and a second switching circuit; a testfixture arranged to receive the first and second transport frames and totest the first and second DUTs, respectively, when the first and secondtransport frames are engaged with the test fixture, the test fixtureincluding a test fixture power supply; and a switching controller incommunication with the first and second switching circuits and arrangedto generate first and second power switching signals; the firstswitching circuit arranged to switch from the first transport framepower supply to the test fixture power supply in response to receiving afirst power switching signal indicating satisfaction of the pre-testingcondition, and arranged to switch from the test fixture power supply tothe first transport frame power supply in response to receiving a secondpower switching signal indicating completion of a testing stage for thefirst DUT, the switching controller arranged to initiate power switchingof power supplied by the test fixture power supply from the firsttransport frame to the second transport frame to begin a testing stagefor the second DUT, the second switching circuit arranged to switch fromthe second transport frame power supply to the test fixture power supplyin response to receiving a third power switching signal indicatingsatisfaction of a second pre-testing condition, and arranged to switchfrom the test fixture power supply to the second transport frame powersupply in response to receiving a fourth power switching signalindicating completion of the testing stage for the second DUT, theswitching controller arranged to generate the third and fourth powerswitching signals.
 25. A method of power switching in a system fortesting first and second battery-powered electronic devices-under-test(DUTs), the system including first and second transport frames forreceiving the first and second DUTs, respectively, and a test fixturearranged to receive the first and second transport frames and to testthe first and second DUTs, respectively, when the first and secondtransport frames are engaged with the test fixture, the methodcomprising: providing power to the first DUT in a pre-testing stage viaa first transport frame power supply when the DUT is housed in the firsttransport frame; switching from the first transport frame power supplyto a test fixture power supply in response to receiving a first powerswitching signal indicating satisfaction of a first pre-testingcondition; switching from the test fixture power supply to the firsttransport frame power supply in response to receiving a second powerswitching signal indicating completion of a testing stage for the firstDUT; switching from the second transport frame power supply to a testfixture power supply in response to receiving a third power switchingsignal indicating satisfaction of a second pre-testing condition; andswitching from the test fixture power supply to the second transportframe power supply in response to receiving a fourth power switchingsignal indicating completion of a testing stage for the second DUT.